英语翻译我这里还有一部分内容不是很明了,能否请你帮忙翻译一下,A project to sequence the bov
英语翻译
我这里还有一部分内容不是很明了,能否请你帮忙翻译一下,
A project to sequence the bovine genome started in 2003 and the first draft
sequence with three-fold coverage of the genome was made publicly available in
November 2004.首先是这一句,其中“ three-fold coverage of the genome”想了很久都没有明白到底是什么意思,
2.4.4 MAPPING POPULATIONS
The second requirement to map QTLs,in addition to the genetic markers,is families
segregating and recorded for the traits of interest.Unfortunately,the range of traits
routinely recorded in commercial populations is very limited,and through necessity
has focused on simple traits,such as growth rates and milk yields.An additional
consideration is that traits are often sex specific,and although selection is applied
most strongly in the males,because of artificial insemination(AI),the trait is often
expressed in the females.In the case of meat quality accurate measurements of the
traits can only be done postslaughter,and thus cannot be made in the animals
intended for breeding.
The structure of the commercial dairy population includes a large number of
half-sib cows produced by AI from a limited number of elite bulls.This population
structure is particularly appropriate for mapping QTL.The genetic contribution of
bulls to milk production traits can be determined with high accuracy by measuring
the phenotypes of their daughters.Bulls with high breeding value are then used
extensively through AI to improve the dairy cow population.The sons of bulls with
high breeding values are in turn used as AI sires to produce a large number of
daughters.Georges et al.(1995)used the U.S.Holstein population to map QTL
involved in milk yield.Five QTL for dairy-associated traits were identified,many
of which have been confirmed independently in subsequent studies in other popu-
lations(e.g.,Kuhn,Freyer,Weikard,Goldammer,and Schwerin 1999;Wiener,
Maclean,Williams,and Woolliams 2000).还有这一章节,完全不明白在讲什么,如果你方便的话,能否帮我也翻译一下,实在是很急,没有头绪,麻烦你了!